The invention relates to a communication system according to the preamble of patent claim 1, and also to interfaces matched thereto.
A system of this type is known from German Offenlegungsschrift 3,033,871. This communication system consists of a first subscriber network in which the voice processing is executed with pulse code modulation and of a second subscriber network in which the voice processing is executed with delta modulation. The subscribers of the networks are connected to one another across an interface, with a signaling converter being provided in the interface. The subscriber terminals of the first network, which are equipped with a cryptogenerator, additionally have a delta modulation device corresponding to the second network for voice processing.